A Hong Kong court has jailed a woman for smuggling baby formula, the first time anybody has been sent to prison under the city’s ban on unlicensed milk powder export, officials said Tuesday.

The 37-year-old woman, whose nationality has not been disclosed, was jailed for five weeks after being found with four boxes of baby milk formula weighing 3.2 kilograms at the border crossing between Hong Kong and its neighboring mainland Chinese city of Shenzhen Sunday.

Hong Kong barred people from taking more than 1.8 kilograms of formula out of the city in March after a rush on milk powder by Chinese parents, distrustful of domestic milk brands due to a 2008 scandal involving formula tainted with melamine that killed six children and sickened 300,000 others.

Their concern triggered demand which saw shelves emptied around the world.

Hong Kong’s controversial ban aimed to crack down on “parallel traders” who sell the milk powder for a profit in China.

“It is the first case of immediate imprisonment,” a government spokeswoman told AFP Tuesday.

The woman pleaded guilty to “illegally exporting powdered formula for infants and children … from Hong Kong,” a government statement said late Monday.

“She was sentenced to immediate imprisonment of 35 days,” it said.

She had been convicted three times previously for the same offense and had been given a 21-day suspended prison sentence in November.

The government says offenders could face a fine of $64,282 and two years’ imprisonment.

Although Hong Kong was returned to Chinese rule in 1997, it maintains a semi-autonomous status with its own laws and customs rules and promotes itself as a free port.

Hundreds of mainland Chinese were seen stuffing tins of baby milk powder into large bags and boxes near train stations at the border before the ban. The majority of them were parallel traders who travel to Hong Kong daily by train.